A practical and efficient method for the direct trifluoromethylthiolation of unactivated C(sp3)H bonds by AgSCF3/K2S2O8 under mild conditions is described. The reaction has a good functional‐group tolerance and good selectivity. Initial mechanistic investigations indicate that the reaction may involve a radical process in which K2S2O8 plays key roles in both the activation of the C(sp3)H bond and the oxidation of AgSCF3. Direct and mild: A variety of alkyltrifluoromethylthioethers were efficiently synthesized by direct trifluoromethylthiolation of unactivated C(sp3)H bonds under mild reaction conditions. The reagent system comprises AgSCF3 and K2S2O8, the latter of which both activates the C(sp3)H bond and oxidizes AgSCF3. The reaction has a broad substrate scope with good functional‐group tolerance and good selectivity.